content/browser/dom_storage/dom_storage_area_unittest.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/bind.h"
   6 #include "base/files/file_util.h"
   7 #include "base/files/scoped_temp_dir.h"
   8 #include "base/message_loop/message_loop.h"
   9 #include "base/strings/utf_string_conversions.h"
  10 #include "base/thread_task_runner_handle.h"
  11 #include "base/threading/sequenced_worker_pool.h"
  12 #include "base/time/time.h"
  13 #include "content/browser/dom_storage/dom_storage_area.h"
  14 #include "content/browser/dom_storage/dom_storage_database.h"
  15 #include "content/browser/dom_storage/dom_storage_database_adapter.h"
  16 #include "content/browser/dom_storage/dom_storage_task_runner.h"
  17 #include "content/browser/dom_storage/local_storage_database_adapter.h"
  18 #include "content/common/dom_storage/dom_storage_types.h"
  19 #include "content/public/browser/browser_thread.h"
  20 #include "testing/gtest/include/gtest/gtest.h"
  21
  22 using base::ASCIIToUTF16;
  23
  24 namespace content {
  25
  26 class DOMStorageAreaTest : public testing::Test {
  27  public:
  28   DOMStorageAreaTest()
  29     : kOrigin(GURL("http://dom_storage/")),
  30       kKey(ASCIIToUTF16("key")),
  31       kValue(ASCIIToUTF16("value")),
  32       kKey2(ASCIIToUTF16("key2")),
  33       kValue2(ASCIIToUTF16("value2")) {
  34   }
  35
  36   const GURL kOrigin;
  37   const base::string16 kKey;
  38   const base::string16 kValue;
  39   const base::string16 kKey2;
  40   const base::string16 kValue2;
  41
  42   // Method used in the CommitTasks test case.
  43   void InjectedCommitSequencingTask1(
  44       const scoped_refptr<DOMStorageArea>& area) {
  45     // At this point the StartCommitTimer task has run and
  46     // the OnCommitTimer task is queued. We want to inject after
  47     // that.
  48     base::MessageLoop::current()->PostTask(
  49         FROM_HERE,
  50         base::Bind(&DOMStorageAreaTest::InjectedCommitSequencingTask2,
  51                    base::Unretained(this),
  52                    area));
  53   }
  54
  55   void InjectedCommitSequencingTask2(
  56       const scoped_refptr<DOMStorageArea>& area) {
  57     // At this point the OnCommitTimer has run.
  58     // Verify that it put a commit in flight.
  59     EXPECT_EQ(1, area->commit_batches_in_flight_);
  60     EXPECT_FALSE(area->commit_batch_.get());
  61     EXPECT_TRUE(area->HasUncommittedChanges());
  62     // Make additional change and verify that a new commit batch
  63     // is created for that change.
  64     base::NullableString16 old_value;
  65     EXPECT_TRUE(area->SetItem(kKey2, kValue2, &old_value));
  66     EXPECT_TRUE(area->commit_batch_.get());
  67     EXPECT_EQ(1, area->commit_batches_in_flight_);
  68     EXPECT_TRUE(area->HasUncommittedChanges());
  69   }
  70
  71   // Class used in the CommitChangesAtShutdown test case.
  72   class VerifyChangesCommittedDatabase : public DOMStorageDatabase {
  73    public:
  74     VerifyChangesCommittedDatabase() {}
  75     ~VerifyChangesCommittedDatabase() override {
  76       const base::string16 kKey(ASCIIToUTF16("key"));
  77       const base::string16 kValue(ASCIIToUTF16("value"));
  78       DOMStorageValuesMap values;
  79       ReadAllValues(&values);
  80       EXPECT_EQ(1u, values.size());
  81       EXPECT_EQ(kValue, values[kKey].string());
  82     }
  83   };
  84
  85  private:
  86   base::MessageLoop message_loop_;
  87 };
  88
  89 TEST_F(DOMStorageAreaTest, DOMStorageAreaBasics) {
  90   scoped_refptr<DOMStorageArea> area(
  91       new DOMStorageArea(1, std::string(), kOrigin, NULL, NULL));
  92   base::string16 old_value;
  93   base::NullableString16 old_nullable_value;
  94   scoped_refptr<DOMStorageArea> copy;
  95
  96   // We don't focus on the underlying DOMStorageMap functionality
  97   // since that's covered by seperate unit tests.
  98   EXPECT_EQ(kOrigin, area->origin());
  99   EXPECT_EQ(1, area->namespace_id());
 100   EXPECT_EQ(0u, area->Length());
 101   EXPECT_TRUE(area->SetItem(kKey, kValue, &old_nullable_value));
 102   EXPECT_TRUE(area->SetItem(kKey2, kValue2, &old_nullable_value));
 103   EXPECT_FALSE(area->HasUncommittedChanges());
 104
 105   // Verify that a copy shares the same map.
 106   copy = area->ShallowCopy(2, std::string());
 107   EXPECT_EQ(kOrigin, copy->origin());
 108   EXPECT_EQ(2, copy->namespace_id());
 109   EXPECT_EQ(area->Length(), copy->Length());
 110   EXPECT_EQ(area->GetItem(kKey).string(), copy->GetItem(kKey).string());
 111   EXPECT_EQ(area->Key(0).string(), copy->Key(0).string());
 112   EXPECT_EQ(copy->map_.get(), area->map_.get());
 113
 114   // But will deep copy-on-write as needed.
 115   EXPECT_TRUE(area->RemoveItem(kKey, &old_value));
 116   EXPECT_NE(copy->map_.get(), area->map_.get());
 117   copy = area->ShallowCopy(2, std::string());
 118   EXPECT_EQ(copy->map_.get(), area->map_.get());
 119   EXPECT_TRUE(area->SetItem(kKey, kValue, &old_nullable_value));
 120   EXPECT_NE(copy->map_.get(), area->map_.get());
 121   copy = area->ShallowCopy(2, std::string());
 122   EXPECT_EQ(copy->map_.get(), area->map_.get());
 123   EXPECT_NE(0u, area->Length());
 124   EXPECT_TRUE(area->Clear());
 125   EXPECT_EQ(0u, area->Length());
 126   EXPECT_NE(copy->map_.get(), area->map_.get());
 127
 128   // Verify that once Shutdown(), behaves that way.
 129   area->Shutdown();
 130   EXPECT_TRUE(area->is_shutdown_);
 131   EXPECT_FALSE(area->map_.get());
 132   EXPECT_EQ(0u, area->Length());
 133   EXPECT_TRUE(area->Key(0).is_null());
 134   EXPECT_TRUE(area->GetItem(kKey).is_null());
 135   EXPECT_FALSE(area->SetItem(kKey, kValue, &old_nullable_value));
 136   EXPECT_FALSE(area->RemoveItem(kKey, &old_value));
 137   EXPECT_FALSE(area->Clear());
 138 }
 139
 140 TEST_F(DOMStorageAreaTest, BackingDatabaseOpened) {
 141   const int64 kSessionStorageNamespaceId = kLocalStorageNamespaceId + 1;
 142   base::ScopedTempDir temp_dir;
 143   ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
 144   const base::FilePath kExpectedOriginFilePath = temp_dir.path().Append(
 145       DOMStorageArea::DatabaseFileNameFromOrigin(kOrigin));
 146
 147   // No directory, backing should be null.
 148   {
 149     scoped_refptr<DOMStorageArea> area(
 150         new DOMStorageArea(kOrigin, base::FilePath(), NULL));
 151     EXPECT_EQ(NULL, area->backing_.get());
 152     EXPECT_TRUE(area->is_initial_import_done_);
 153     EXPECT_FALSE(base::PathExists(kExpectedOriginFilePath));
 154   }
 155
 156   // Valid directory and origin but no session storage backing. Backing should
 157   // be null.
 158   {
 159     scoped_refptr<DOMStorageArea> area(
 160         new DOMStorageArea(kSessionStorageNamespaceId, std::string(), kOrigin,
 161                            NULL, NULL));
 162     EXPECT_EQ(NULL, area->backing_.get());
 163     EXPECT_TRUE(area->is_initial_import_done_);
 164
 165     base::NullableString16 old_value;
 166     EXPECT_TRUE(area->SetItem(kKey, kValue, &old_value));
 167     ASSERT_TRUE(old_value.is_null());
 168
 169     // Check that saving a value has still left us without a backing database.
 170     EXPECT_EQ(NULL, area->backing_.get());
 171     EXPECT_FALSE(base::PathExists(kExpectedOriginFilePath));
 172   }
 173
 174   // This should set up a DOMStorageArea that is correctly backed to disk.
 175   {
 176     scoped_refptr<DOMStorageArea> area(new DOMStorageArea(
 177         kOrigin,
 178         temp_dir.path(),
 179         new MockDOMStorageTaskRunner(base::MessageLoopProxy::current().get())));
 180
 181     EXPECT_TRUE(area->backing_.get());
 182     DOMStorageDatabase* database = static_cast<LocalStorageDatabaseAdapter*>(
 183         area->backing_.get())->db_.get();
 184     EXPECT_FALSE(database->IsOpen());
 185     EXPECT_FALSE(area->is_initial_import_done_);
 186
 187     // Inject an in-memory db to speed up the test.
 188     // We will verify that something is written into the database but not
 189     // that a file is written to disk - DOMStorageDatabase unit tests cover
 190     // that.
 191     area->backing_.reset(new LocalStorageDatabaseAdapter());
 192
 193     // Need to write something to ensure that the database is created.
 194     base::NullableString16 old_value;
 195     EXPECT_TRUE(area->SetItem(kKey, kValue, &old_value));
 196     ASSERT_TRUE(old_value.is_null());
 197     EXPECT_TRUE(area->is_initial_import_done_);
 198     EXPECT_TRUE(area->commit_batch_.get());
 199     EXPECT_EQ(0, area->commit_batches_in_flight_);
 200
 201     base::MessageLoop::current()->RunUntilIdle();
 202
 203     EXPECT_FALSE(area->commit_batch_.get());
 204     EXPECT_EQ(0, area->commit_batches_in_flight_);
 205     database = static_cast<LocalStorageDatabaseAdapter*>(
 206         area->backing_.get())->db_.get();
 207     EXPECT_TRUE(database->IsOpen());
 208     EXPECT_EQ(1u, area->Length());
 209     EXPECT_EQ(kValue, area->GetItem(kKey).string());
 210
 211     // Verify the content made it to the in memory database.
 212     DOMStorageValuesMap values;
 213     area->backing_->ReadAllValues(&values);
 214     EXPECT_EQ(1u, values.size());
 215     EXPECT_EQ(kValue, values[kKey].string());
 216   }
 217 }
 218
 219 TEST_F(DOMStorageAreaTest, CommitTasks) {
 220   base::ScopedTempDir temp_dir;
 221   ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
 222
 223   scoped_refptr<DOMStorageArea> area(new DOMStorageArea(
 224       kOrigin,
 225       temp_dir.path(),
 226       new MockDOMStorageTaskRunner(base::MessageLoopProxy::current().get())));
 227   // Inject an in-memory db to speed up the test.
 228   area->backing_.reset(new LocalStorageDatabaseAdapter());
 229
 230   // Unrelated to commits, but while we're here, see that querying Length()
 231   // causes the backing database to be opened and presumably read from.
 232   EXPECT_FALSE(area->is_initial_import_done_);
 233   EXPECT_EQ(0u, area->Length());
 234   EXPECT_TRUE(area->is_initial_import_done_);
 235
 236   DOMStorageValuesMap values;
 237   base::NullableString16 old_value;
 238
 239   // See that changes are batched up.
 240   EXPECT_FALSE(area->commit_batch_.get());
 241   EXPECT_TRUE(area->SetItem(kKey, kValue, &old_value));
 242   EXPECT_TRUE(area->HasUncommittedChanges());
 243   EXPECT_TRUE(area->commit_batch_.get());
 244   EXPECT_FALSE(area->commit_batch_->clear_all_first);
 245   EXPECT_EQ(1u, area->commit_batch_->changed_values.size());
 246   EXPECT_TRUE(area->SetItem(kKey2, kValue2, &old_value));
 247   EXPECT_TRUE(area->commit_batch_.get());
 248   EXPECT_FALSE(area->commit_batch_->clear_all_first);
 249   EXPECT_EQ(2u, area->commit_batch_->changed_values.size());
 250   base::MessageLoop::current()->RunUntilIdle();
 251   EXPECT_FALSE(area->HasUncommittedChanges());
 252   EXPECT_FALSE(area->commit_batch_.get());
 253   EXPECT_EQ(0, area->commit_batches_in_flight_);
 254   // Verify the changes made it to the database.
 255   values.clear();
 256   area->backing_->ReadAllValues(&values);
 257   EXPECT_EQ(2u, values.size());
 258   EXPECT_EQ(kValue, values[kKey].string());
 259   EXPECT_EQ(kValue2, values[kKey2].string());
 260
 261   // See that clear is handled properly.
 262   EXPECT_TRUE(area->Clear());
 263   EXPECT_TRUE(area->commit_batch_.get());
 264   EXPECT_TRUE(area->commit_batch_->clear_all_first);
 265   EXPECT_TRUE(area->commit_batch_->changed_values.empty());
 266   base::MessageLoop::current()->RunUntilIdle();
 267   EXPECT_FALSE(area->commit_batch_.get());
 268   EXPECT_EQ(0, area->commit_batches_in_flight_);
 269   // Verify the changes made it to the database.
 270   values.clear();
 271   area->backing_->ReadAllValues(&values);
 272   EXPECT_TRUE(values.empty());
 273
 274   // See that if changes accrue while a commit is "in flight"
 275   // those will also get committed.
 276   EXPECT_TRUE(area->SetItem(kKey, kValue, &old_value));
 277   EXPECT_TRUE(area->HasUncommittedChanges());
 278   // At this point the StartCommitTimer task has been posted to the after
 279   // startup task queue. We inject another task in the queue that will
 280   // execute when the CommitChanges task is inflight. From within our
 281   // injected task, we'll make an additional SetItem() call and verify
 282   // that a new commit batch is created for that additional change.
 283   BrowserThread::PostAfterStartupTask(
 284       FROM_HERE, base::ThreadTaskRunnerHandle::Get(),
 285       base::Bind(&DOMStorageAreaTest::InjectedCommitSequencingTask1,
 286                  base::Unretained(this),
 287                  area));
 288   base::MessageLoop::current()->RunUntilIdle();
 289   EXPECT_TRUE(area->HasOneRef());
 290   EXPECT_FALSE(area->HasUncommittedChanges());
 291   // Verify the changes made it to the database.
 292   values.clear();
 293   area->backing_->ReadAllValues(&values);
 294   EXPECT_EQ(2u, values.size());
 295   EXPECT_EQ(kValue, values[kKey].string());
 296   EXPECT_EQ(kValue2, values[kKey2].string());
 297 }
 298
 299 TEST_F(DOMStorageAreaTest, CommitChangesAtShutdown) {
 300   base::ScopedTempDir temp_dir;
 301   ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
 302   scoped_refptr<DOMStorageArea> area(new DOMStorageArea(
 303       kOrigin,
 304       temp_dir.path(),
 305       new MockDOMStorageTaskRunner(base::MessageLoopProxy::current().get())));
 306
 307   // Inject an in-memory db to speed up the test and also to verify
 308   // the final changes are commited in it's dtor.
 309   static_cast<LocalStorageDatabaseAdapter*>(area->backing_.get())->db_.reset(
 310       new VerifyChangesCommittedDatabase());
 311
 312   DOMStorageValuesMap values;
 313   base::NullableString16 old_value;
 314   EXPECT_TRUE(area->SetItem(kKey, kValue, &old_value));
 315   EXPECT_TRUE(area->HasUncommittedChanges());
 316   area->backing_->ReadAllValues(&values);
 317   EXPECT_TRUE(values.empty());  // not committed yet
 318   area->Shutdown();
 319   base::MessageLoop::current()->RunUntilIdle();
 320   EXPECT_TRUE(area->HasOneRef());
 321   EXPECT_FALSE(area->backing_.get());
 322   // The VerifyChangesCommittedDatabase destructor verifies values
 323   // were committed.
 324 }
 325
 326 TEST_F(DOMStorageAreaTest, DeleteOrigin) {
 327   base::ScopedTempDir temp_dir;
 328   ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
 329   scoped_refptr<DOMStorageArea> area(new DOMStorageArea(
 330       kOrigin,
 331       temp_dir.path(),
 332       new MockDOMStorageTaskRunner(base::MessageLoopProxy::current().get())));
 333
 334   // This test puts files on disk.
 335   base::FilePath db_file_path = static_cast<LocalStorageDatabaseAdapter*>(
 336       area->backing_.get())->db_->file_path();
 337   base::FilePath db_journal_file_path =
 338       DOMStorageDatabase::GetJournalFilePath(db_file_path);
 339
 340   // Nothing bad should happen when invoked w/o any files on disk.
 341   area->DeleteOrigin();
 342   EXPECT_FALSE(base::PathExists(db_file_path));
 343
 344   // Commit something in the database and then delete.
 345   base::NullableString16 old_value;
 346   area->SetItem(kKey, kValue, &old_value);
 347   base::MessageLoop::current()->RunUntilIdle();
 348   EXPECT_TRUE(base::PathExists(db_file_path));
 349   area->DeleteOrigin();
 350   EXPECT_EQ(0u, area->Length());
 351   EXPECT_FALSE(base::PathExists(db_file_path));
 352   EXPECT_FALSE(base::PathExists(db_journal_file_path));
 353
 354   // Put some uncommitted changes to a non-existing database in
 355   // and then delete. No file ever gets created in this case.
 356   area->SetItem(kKey, kValue, &old_value);
 357   EXPECT_TRUE(area->HasUncommittedChanges());
 358   EXPECT_EQ(1u, area->Length());
 359   area->DeleteOrigin();
 360   EXPECT_TRUE(area->HasUncommittedChanges());
 361   EXPECT_EQ(0u, area->Length());
 362   base::MessageLoop::current()->RunUntilIdle();
 363   EXPECT_FALSE(area->HasUncommittedChanges());
 364   EXPECT_FALSE(base::PathExists(db_file_path));
 365
 366   // Put some uncommitted changes to a an existing database in
 367   // and then delete.
 368   area->SetItem(kKey, kValue, &old_value);
 369   base::MessageLoop::current()->RunUntilIdle();
 370   EXPECT_TRUE(base::PathExists(db_file_path));
 371   area->SetItem(kKey2, kValue2, &old_value);
 372   EXPECT_TRUE(area->HasUncommittedChanges());
 373   EXPECT_EQ(2u, area->Length());
 374   area->DeleteOrigin();
 375   EXPECT_TRUE(area->HasUncommittedChanges());
 376   EXPECT_EQ(0u, area->Length());
 377   base::MessageLoop::current()->RunUntilIdle();
 378   EXPECT_FALSE(area->HasUncommittedChanges());
 379   // Since the area had uncommitted changes at the time delete
 380   // was called, the file will linger until the shutdown time.
 381   EXPECT_TRUE(base::PathExists(db_file_path));
 382   area->Shutdown();
 383   base::MessageLoop::current()->RunUntilIdle();
 384   EXPECT_FALSE(base::PathExists(db_file_path));
 385 }
 386
 387 TEST_F(DOMStorageAreaTest, PurgeMemory) {
 388   base::ScopedTempDir temp_dir;
 389   ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
 390   scoped_refptr<DOMStorageArea> area(new DOMStorageArea(
 391       kOrigin,
 392       temp_dir.path(),
 393       new MockDOMStorageTaskRunner(base::MessageLoopProxy::current().get())));
 394
 395   // Inject an in-memory db to speed up the test.
 396   area->backing_.reset(new LocalStorageDatabaseAdapter());
 397
 398   // Unowned ptrs we use to verify that 'purge' has happened.
 399   DOMStorageDatabase* original_backing =
 400       static_cast<LocalStorageDatabaseAdapter*>(
 401           area->backing_.get())->db_.get();
 402   DOMStorageMap* original_map = area->map_.get();
 403
 404   // Should do no harm when called on a newly constructed object.
 405   EXPECT_FALSE(area->is_initial_import_done_);
 406   area->PurgeMemory();
 407   EXPECT_FALSE(area->is_initial_import_done_);
 408   DOMStorageDatabase* new_backing = static_cast<LocalStorageDatabaseAdapter*>(
 409       area->backing_.get())->db_.get();
 410   EXPECT_EQ(original_backing, new_backing);
 411   EXPECT_EQ(original_map, area->map_.get());
 412
 413   // Should not do anything when commits are pending.
 414   base::NullableString16 old_value;
 415   area->SetItem(kKey, kValue, &old_value);
 416   EXPECT_TRUE(area->is_initial_import_done_);
 417   EXPECT_TRUE(area->HasUncommittedChanges());
 418   area->PurgeMemory();
 419   EXPECT_TRUE(area->is_initial_import_done_);
 420   EXPECT_TRUE(area->HasUncommittedChanges());
 421   new_backing = static_cast<LocalStorageDatabaseAdapter*>(
 422       area->backing_.get())->db_.get();
 423   EXPECT_EQ(original_backing, new_backing);
 424   EXPECT_EQ(original_map, area->map_.get());
 425
 426   // Commit the changes from above,
 427   base::MessageLoop::current()->RunUntilIdle();
 428   EXPECT_FALSE(area->HasUncommittedChanges());
 429   new_backing = static_cast<LocalStorageDatabaseAdapter*>(
 430       area->backing_.get())->db_.get();
 431   EXPECT_EQ(original_backing, new_backing);
 432   EXPECT_EQ(original_map, area->map_.get());
 433
 434   // Should drop caches and reset database connections
 435   // when invoked on an area that's loaded up primed.
 436   area->PurgeMemory();
 437   EXPECT_FALSE(area->is_initial_import_done_);
 438   new_backing = static_cast<LocalStorageDatabaseAdapter*>(
 439       area->backing_.get())->db_.get();
 440   EXPECT_NE(original_backing, new_backing);
 441   EXPECT_NE(original_map, area->map_.get());
 442 }
 443
 444 TEST_F(DOMStorageAreaTest, DatabaseFileNames) {
 445   struct {
 446     const char* origin;
 447     const char* file_name;
 448     const char* journal_file_name;
 449   } kCases[] = {
 450     { "https://www.google.com/",
 451       "https_www.google.com_0.localstorage",
 452       "https_www.google.com_0.localstorage-journal" },
 453     { "http://www.google.com:8080/",
 454       "http_www.google.com_8080.localstorage",
 455       "http_www.google.com_8080.localstorage-journal" },
 456     { "file:///",
 457       "file__0.localstorage",
 458       "file__0.localstorage-journal" },
 459   };
 460
 461   for (size_t i = 0; i < arraysize(kCases); ++i) {
 462     GURL origin = GURL(kCases[i].origin).GetOrigin();
 463     base::FilePath file_name =
 464         base::FilePath().AppendASCII(kCases[i].file_name);
 465     base::FilePath journal_file_name =
 466         base::FilePath().AppendASCII(kCases[i].journal_file_name);
 467
 468     EXPECT_EQ(file_name,
 469               DOMStorageArea::DatabaseFileNameFromOrigin(origin));
 470     EXPECT_EQ(origin,
 471               DOMStorageArea::OriginFromDatabaseFileName(file_name));
 472     EXPECT_EQ(journal_file_name,
 473               DOMStorageDatabase::GetJournalFilePath(file_name));
 474   }
 475
 476   // Also test some DOMStorageDatabase::GetJournalFilePath cases here.
 477   base::FilePath parent = base::FilePath().AppendASCII("a").AppendASCII("b");
 478   EXPECT_EQ(
 479       parent.AppendASCII("file-journal"),
 480       DOMStorageDatabase::GetJournalFilePath(parent.AppendASCII("file")));
 481   EXPECT_EQ(
 482       base::FilePath().AppendASCII("-journal"),
 483       DOMStorageDatabase::GetJournalFilePath(base::FilePath()));
 484   EXPECT_EQ(
 485       base::FilePath().AppendASCII(".extensiononly-journal"),
 486       DOMStorageDatabase::GetJournalFilePath(
 487           base::FilePath().AppendASCII(".extensiononly")));
 488 }
 489
 490 TEST_F(DOMStorageAreaTest, RateLimiter) {
 491   // Limit to 1000 samples per second
 492   DOMStorageArea::RateLimiter rate_limiter(
 493       1000, base::TimeDelta::FromSeconds(1));
 494
 495   // No samples have been added so no time/delay should be needed.
 496   EXPECT_EQ(base::TimeDelta(),
 497             rate_limiter.ComputeTimeNeeded());
 498   EXPECT_EQ(base::TimeDelta(),
 499             rate_limiter.ComputeDelayNeeded(base::TimeDelta()));
 500   EXPECT_EQ(base::TimeDelta(),
 501             rate_limiter.ComputeDelayNeeded(base::TimeDelta::FromDays(1)));
 502
 503   // Add a seconds worth of samples.
 504   rate_limiter.add_samples(1000);
 505   EXPECT_EQ(base::TimeDelta::FromSeconds(1),
 506             rate_limiter.ComputeTimeNeeded());
 507   EXPECT_EQ(base::TimeDelta::FromSeconds(1),
 508             rate_limiter.ComputeDelayNeeded(base::TimeDelta()));
 509   EXPECT_EQ(base::TimeDelta(),
 510             rate_limiter.ComputeDelayNeeded(base::TimeDelta::FromSeconds(1)));
 511   EXPECT_EQ(base::TimeDelta::FromMilliseconds(250),
 512             rate_limiter.ComputeDelayNeeded(
 513                 base::TimeDelta::FromMilliseconds(750)));
 514   EXPECT_EQ(base::TimeDelta(),
 515             rate_limiter.ComputeDelayNeeded(
 516                 base::TimeDelta::FromDays(1)));
 517
 518   // And another half seconds worth.
 519   rate_limiter.add_samples(500);
 520   EXPECT_EQ(base::TimeDelta::FromMilliseconds(1500),
 521             rate_limiter.ComputeTimeNeeded());
 522   EXPECT_EQ(base::TimeDelta::FromMilliseconds(1500),
 523             rate_limiter.ComputeDelayNeeded(base::TimeDelta()));
 524   EXPECT_EQ(base::TimeDelta::FromMilliseconds(500),
 525             rate_limiter.ComputeDelayNeeded(base::TimeDelta::FromSeconds(1)));
 526   EXPECT_EQ(base::TimeDelta::FromMilliseconds(750),
 527             rate_limiter.ComputeDelayNeeded(
 528                 base::TimeDelta::FromMilliseconds(750)));
 529   EXPECT_EQ(base::TimeDelta(),
 530             rate_limiter.ComputeDelayNeeded(
 531                 base::TimeDelta::FromMilliseconds(1500)));
 532   EXPECT_EQ(base::TimeDelta(),
 533             rate_limiter.ComputeDelayNeeded(
 534                 base::TimeDelta::FromDays(1)));
 535 }
 536
 537 }  // namespace content